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Characterization of protein C receptor expression in monocytes
Author(s) -
Galligan Leeona,
Livingstone Wendy,
Volkov Yuri,
Hokamp Karsten,
Murphy Ciaran,
Lawler Mark,
Fukudome Kenji,
Smith Owen
Publication year - 2001
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1046/j.1365-2141.2001.03187.x
Subject(s) - endothelial protein c receptor , protein c , lipopolysaccharide , monocyte , cytokine , tumor necrosis factor alpha , receptor , microbiology and biotechnology , biology , tissue factor , thromboplastin , immunology , thrombin , medicine , coagulation , platelet , biochemistry , psychiatry
Many sequelae associated with endotoxaemic‐induced shock result from excessive production of the cytokine mediators, tumour necrosis factor alpha (TNF‐α), interleukin 1 (IL‐1) and IL‐6 from lipopolysaccharide (LPS)‐activated monocytes. Protein C (PC)/activated protein C (APC) has potent cytokine‐modifying properties and is protective in animal models and human clinical trials of sepsis. The precise mechanism by which this anti‐inflammatory response is achieved remains unknown; however, the recently described endothelial protein C receptor (EPCR) appears to be essential for this function. The pivotal role that monocytes play in the pathophysiology of septic shock led us to investigate the possible expression of a protein C receptor on the monocyte membrane. We used similarity algorithms to screen human sequence databases for paralogues of the EPCR but found none. However, using reverse transcription–polymerase chain reaction (RT–PCR), we detected an mRNA transcribed in primary human monocytes and THP1 cells that was identical to human EPCR mRNA. We also used immunocytochemical analysis to demonstrate the expression of a protein C receptor on the surface of monocytes encoded by the same gene as EPCR. These results confirm a new member of the protein C pathway involving primary monocytes. Further characterization will be necessary to compare and contrast its biological properties with those of EPCR.